if you walk away
by a mountain of gideon's scones
Summary: Tessa has a decision to make: Jem or Will. Which one it will be depends on how she feels - or how she has felt for the entire time. /for SisterGrimmErin. R


**AN: **This is my fic for the "summer or bust exchange" on The Towers of Alicante forum & it's for **Sister Grimm Erin**

I don't own anything.

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She's struggling with her emotions.

Tessa Gray has always been someone who can think through things logically, someone who considers all angles of a problem before then concluding what is the best option – and yet here, now, when more than just her own happiness rides on her decision, she doesn't know what to do. Part of her wants to go with Jem (he's asked her to _marry_ him, after all) because he deserves it, and he makes her laugh, right? He's the one who can secure her future – or as secure as her future can be, after all – and she knows that he can make her happy. He's sweet and charming and everything that a perfect boyfriend ought to be…but…but—

—but he isn't Will.

The other (_stronger_)part of Tessa that doesn't love Jem loves Will, the rash and impulsive boy who makes no sense to her; he's sarcastic and bitter, but she knows that it's just an appearance: he's had to appear something he isn't for all these years, for fear of something that didn't really exist, and that's left him a complete mystery to Tessa. He's a book yet to be read, the cover unopened and locking in the mysteries that someone is just _dying_ to unlock. Will Herondale is more than just the tortured soul he appears to be – and it's something that she wants to do, to sit down and be able to unlock the window into his soul, to see what he's really like.

And that leaves her at an impasse; does she follow her heart, follow it to where she knows Will is, or does she do the _right_ thing, because Jem doesn't have long left, and anyway, she does feel something for him? It's a decision that tortures her long into the night, every night, be it in the Institute as they prepare to fight the clockwork army, or on one of their long journeys to the north to discover more information.

She knows that she'll have to decide soon, that she's going to be breaking one of their hearts beyond repair, and that every second that passes destroys Will that little bit more – but it makes Jem happier, causing a new, more radiant spark to be emitted from him.

(Can she allow this to continue, or does her _heart_ want to make Will happy, more than it wants to make Jem feel the same?)

_~x~_

The next morning, Tessa wakes up and realises that she has to make a decision: it's been seven weeks already, and yet she's still hanging on tenterhooks around the pair of them, because she's scared that she could say something that could make them realise that everything isn't as it seems. And yet now feels the right time to be disengaging herself from one of them, because even now, she's dreaming of what it would be like to kiss Will, to imagine making the decision to kiss him anywhere but the mouth, and that's not what a good fiancée does, is it?

"Good morning, Tessa." Will is, as per usual, polite and courteous as he greets Tessa at the breakfast table, yet there's the invisible wall present that has been since she told him that she had accepted Jem's marriage proposal. "Would you like some tea?"

It's just the two of them, and she can't help but feel slightly awkward as she sits down across the table from him, even though there's a note in her dress pocket that she needs to give him. Now would be the perfect time to give him it, granted, yet…she almost doesn't want to. She doesn't want _today_ to be the day that she breaks one of the Parabatai's hearts – then again, she doesn't want that day to be any day. All she's doing is putting it off, trying to prolong the ability to have them both in her life, and yet this is only making the situation more poisonous, making the decision more absolute and the breaking away of one of them completely permanent.

"Why yes, thank you," she replies, her tone indifferent because she doesn't want to give him the impression that she's mad with him. Part of her is – she's mad because he's there, and he's so complicated, so that makes her love him even _more_ – but the rest of her doesn't know _what_ to think, because nothing makes any sense to her anymore. Only a few weeks ago, she was just friends with them both, slightly more than that with the sarcastic version Will once was, and growing closer to the more innocent, easier to love Jem.

Now, everything is turning on its head, and no longer do the simpler things in her life make absolute sense to Tessa. Now, even accepting a cup of tea from someone she isn't meant to love, yet does anyway, seems wrong – it shouldn't be, yet she can't help think that it is, due to everything that's going on in her mind. Anything and everything seems as though it has the potential to change, to warp itself to become something that could potentially harm her.

(That's how she feels about the two boys, yet she knows that it would hurt her more to leave them _both_, than it will to leave behind only one; part of her loves Will, part of her loves Jem, and the rest of her wishes that she was strong enough to be independent.)

Tessa's eyes meet Will's, and for one second that seems like a lifetime, she can see into his soul; she can see past the façade he shows the rest of the world, even now, and it startles her – she never thought he could feel so _much_ as what she can see.

It's this moment that she decides it's prudent to hand him the note to meet her on the balcony on the third floor of this guest house, just along from his sister's room, at midnight, yet she doesn't say why she wants to meet him. Tessa knows that Will is smart enough to figure it out without needing it spelling out to him, and for that, she is almost grateful; it means she doesn't have to explain what she's doing, besides to tell him that she wants to be with him – or that she never wants to see him again.

"Here," she whispers, handing the small envelope the table hastily, as though it burns her hand to hold it for too long, "don't read it here. And don't mention it, _please_," she stops suddenly as the door opens, the urgency in her tone that he shouldn't even acknowledge its existence until he is alone evident to Will – or, at least she hopes it is.

For once, his dark eyes show nothing but complete and utter seriousness, there being nothing that would suggest to Tessa that he would break his unspoken word: he will not tell Jem about the letter, and she can't put into words in her own mind how grateful she is for that.

(But gratefulness won't help her make up her mind – and, in all honesty, she doesn't know what will.)

_~x~_

It comes down to ducks.

Ducks, birds which spend an inane amount of time in water, are the catalyst in Tessa's mind as to who she 'chooses' – rather, which heart she _isn't_ going to break – because they're the physical proof of something she barely knows.

They show her that Will has weaknesses, that he isn't the completely strong and independent man that he pretends to be; they're not the be all and end all of fears – rather, they're something rather minor in their world of demons and Downworlders – but they're something tangible and _real_. Ducks show Tessa that, really, all Will has wanted is someone to notice his inner qualms, but that he thought he could avoid that by showcasing the more trivial fears, to hide the rest.

Perhaps she's reading far too deeply into the meaning of Will's hatred of ducks, but they make her realise that she always knew who she was going to choose, and they remind her that it's sometimes the most obvious and simplistic things that can make minds up about who to spend time with.

(Though she knows that if it had been _Jem_ who was scared of ducks, she wouldn't be choosing him; it's just the luck of the draw this, isn't it?)

_~x~_

That night, as the hour is approaching eight in the evening, Tessa has to go and tell Jem what she's going to do. Her engagement ring sits heavily on her left hand, and if it could feel, she knows that it would be expressing its utmost sorrow at the turning of events.

"Hello, Tessa!" Jem is happy to see her, as usual, and sets aside his book as she enters the room. Not even the solemn expression on her face can dull the radiance he emits when he sees her, and all this does is make it that much harder for Tessa – how can she abandon someone who needs her so much, who evidently loves her so dearly?

"I must speak with you," she says urgently, remaining standing in opposition to sitting with him. "I am…I am going to hurt you badly, Jem, but know…know that this wasn't an easy decision to make. Know that I struggled and I struggled, and…and that I don't _know_ what—" she tries to explain without saying that she she's splitting up with him, but he can already tell.

"Hush, Tessa; I know precisely what you are alluding to," he says, the grin sliding from his face. "I know that you are here to return the ring, to tell me that you have chosen Will rather than me. I know everything that you are about to say." There's an air of finality to his voice alongside the desolation he's trying desperately to conceal, as though he doesn't want to carry on the conversation – something backed up when he growls and finds himself throwing something across the room, flinging it into the wall. "I should have _known_ that Will would have you in the end; it was obvious from the beginning! I…I…tell me why you didn't come to this conclusion sooner, Tessa? Because you loved me? Or was it because you didn't want to hurt my feelings, because you didn't want to hurt the idiot?" he sounds bitter and savage by the end, and Tessa finds herself flinching away from Jem: never has he been so angry before – and the anger is directed at himself.

Breathing deeply, she takes a step forwards and rests her hands on his shoulders, forcing him to look at her; he tries to resist, but soon stops when she begins to speak, her breath tickling his neck. "You are not an idiot, James Carstairs; you are someone wonderful, magical, and if…if things were different, then you would always have been the one who I would stay with. But…but we were too late. Before I got to know you, I was angered by Will and that has always stuck with me, his— I shouldn't," she stops herself explaining why she loves Will, because that isn't fair on Jem, is it?

He smiles ruefully as her arms wrap around him, pulling their bodies closer. "Your embrace feels the same as it ever has – as long as I have known you, I mean," he comments, and Tessa can hear the choking in his voice as he holds back the tears. "You're beautiful, Tess, and it kills me to say it, but I should have known that you were always going to end up with Will. I can be as angry as I want, but I knew straight away that you would fall for him, with his dark and mysterious charm. I'm sorry I tried to make you mine."

(There's no doubt in Tessa's mind that Jem means everything he says, but she can't help but feel that there'll be a lot of smashed up furniture in the morning.)

"I am sorry for hurting you," she whispers, taking a step backwards. "And I return this to you, for I am not worthy of wearing it. It takes a special kind of woman to be worthy of you, Jem, and I am certain my actions tonight have proven that I am most certainly not it." In her hand is the engagement ring, and she reaches out to place it into his unmoving hand when he makes no efforts to try and take it from her.

"Rest assured, I shall not be in the way of your happiness any longer, darling Tessa," Jem murmurs, turning away from her to look out of the window at the luminous moon in the night sky. "The demon blood will kill me shortly, for I am confident there is no cure, and I will not try and block your happiness in my last months. You and Will both mean far too much to me; I would never hurt my family, not if I could help it."

She could stay; she could stay and remember the reason she fell in love with him – the charm he exudes, the way that he makes her doubt what is _truly_ good and what is evil, and that easy acceptance that he is going to die – because that's exactly what would make her happy right this moment. But, in the long run, loving Will is what will get her through. And so she can't stay.

"Goodbye, Jem," she whispers before turning away and walking from the room, not trying to conceal the tears in her eyes, or to feel the draught on her finger from the lack of ring.

(Who knew abandoning someone other than your one _true_ love would be so hard?)

_~x~_

He's on the balcony before she is, and Tessa can see the dark haired Herondale staring at the same star-filled sky her ex-fiancé observed earlier in the evening. As she approaches, her hands are clammy and she feels almost as if she is going to faint, because how does she tell him that she _loves_ him, and that she wants to be with him? How is she to explain that whilst he isn't particularly overjoyed, Jem understands, and that it's fine for her to be with him, because they were always meant for one another?

She can't plan for this; she just has to see where words take her.

"Hello, Will," she says as she steps out onto the balcony, watching as he jumps ever so slightly – the usually impeccable Shadowhunter didn't hear her, which is a first. "I…I need to speak to you."

"You're going to tell me that you're running away with Jem, aren't you?" He turns around and levels her off with a look that is neither hurt nor angry – it's empty, and somehow, that hurts Tessa more than anything else. "You want me to cover for you, and when he's dead because he can't be saved, you'll come back and say that it was what he wanted. That's what you want—"

He makes to continue, yet Tessa has had enough of listening to his rambling – something that is probably fuelled by some alcohol earlier in the evening – and so she impulsively reaches out and presses her lips to his. It reminds her of the first time they kissed, and yet there's something more to it, something that makes her think that this is it. This is the true love that everyone wants – and she's found it.

"What was that?" he asks as they break apart, both of them panting slightly. "Did you…Tessa, you're _eng—_" he cuts off suddenly as he notices Tessa's bare ring finger.

"I couldn't be with him any longer, not when I feel this way about you," she explains. "It wasn't right. I…I'm in love with _you_, even though you're sarcastic, evil and ridiculous sometimes. You're an absolute _bastard_ to some people, and your sense of humour is absolutely atrocious, but I love you all the same."

Will laughs, and somehow, Tessa finds herself in his arms, her ear on his chest to hear the steady drumming of his heart. "The bitter words in your mouth that have just been aimed at me will never erase the sweet taste of your lips in my memory, my darling Tessa," he says, and though he's trying to be sarcastic, it won't work anymore. She's got into his shell, and now she can see through everything. "At least I know that whenever you give me another lashing of your tongue, I have the ability to wipe away those memories by kissing you once again, do I not?"

Silence reigns when their eyes meet, an intense look passing between them that cannot be broken by any other disturbance; there's nobody in the world but Tessa and Will, and nothing could ever change that.

(She could never imagine a better, more picturesque kiss than where they are, on the balcony under the stars, and she's glad of that, because when Will kisses her, she knows that there could never be anything better.)

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**AN2:** I'd appreciate it if you didn't favourite without reviewing, even though it's not my best work!

-Vicky xx


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